Poster presentation, P4

Official XXIst International Pigment Cell Conference website - 21-24 Sept 2011, Bordeaux - France | updated: September 04 2011

No evidence of the eumelanic brown phenotype in alpaca (Vicugna pacos)

BACKGROUND AND OBJECTIVES The diversity of alpaca fibre colour is one of its main selling advantages. The aim of this study was to increase understanding of what physical properties of the fibre are contributing to colour. METHODS: Samples of the most common solid alpaca fibre colours were collected from Australian Alpaca Fleece Limited (AAFL) and from the 2009 Western Australian Winter Alpaca Show. The samples were grouped into 11 different colour categories as defined by AAFL. These were assayed using the spectrophotometric method of Ozeki et al. (1996) to identify the relative levels of total melanin and ratio of eumelanin to pheomelanin. RESULTS: There was no significant difference (p = 0.209) between white and light fawn animals in total melanin content (A500nm). There was similarly no significant difference in the eumelanin: pheomelanin ratio (A650nm/A500nm) between white (μ = 0.144) and light fawn (μ = 0.158 p = 0.238), fawn (μ = 0.146 p = 0.428), brown (μ = 0.155 p = 0.208), and red brown samples (μ = 0.155 p = 0.232), all of which were predominantly pheomelanic. Black and grey animals displayed higher levels of total melanin (Average A500/mg hair were 0.413 and 0.289 respectively) and fibre containing more eumelanin (Average A650/A500 were 0.329 and 0.395 respectively) when compared to lighter coloured animals. CONCLUSION: It is probable that the eumelanic brown phenotype is not present in alpacas, because brown alpaca fibres contained predominantly pheomelanic melanin, rather than brown eumelanin. Furthermore, using this method, there is no difference in total melanin content or ratio between animals that are classified as white and light fawn.

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